This type of electrical connector has been known in the art. One such electrical connector is disclosed in Japanese Laid-Open Patent Publication No. H8(1996)-69838. This electrical connector is designed such that after the housing of the electrical connector is placed on a surface of a printed circuit board, the lead portions of the contacts of the electrical connector are soldered to electrically conductive pathways of a circuit pattern which is provided on the circuit board. This electrical connector is constructed such that the end portions (or fixing portions) of a metallic shell which extends laterally over the housing are soldered to grounding pathways provided on the circuit board to ground the electrical connector. In this type of electrical connector, the fixing portions of the electrical connector, which are connected to the grounding circuit of the printed circuit board, are formed in a one-piece body with the shell.
To provide anti-corrosion protection, and thereby to improve the durability of the electrical connector, it is customary to provide this metallic shell with plating. As the shell of the electrical connector comes into contact with the corresponding shell of a matable connector when these two connectors are intermated, it is necessary to harden the surface of the shell for the purpose of improving the durability. Thus, it is typical that nickel plating is applied for this purpose.
However, if the whole shell is plated with nickel, including the fixing portions, which are to be soldered onto respective pathways of the printed circuit board as described above, then the soldering of the shell to the printed circuit board is made difficult because of the nickel plating of the fixing portions. One way to circumvent this problem is that the nickel plating may be applied only to the main body of the shell excluding the fixing portions, and solder plating may be applied to the fixing portions instead. However, it is difficult to practice such a separate plating. If the plating process were attempted in such a way, then the process can be very complicated and may raise the price of the electrical connector substantially.
Alternatively, the fixing portions may be formed as a separate part from the shell, for example, as a fixture, and the main body of the shell and these separately formed fixing portions may be plated separately in the manner described above before they are assembled to the housing of the electrical connector. For example, as shown in FIG. 7, the fixture 98 may comprise a main body 98a, which is formed in a U-like cross section, and a fixing portion 98b, which is provided on the lower end of the main body 98a such that the fixture 98 is capable of attaching itself to a printed circuit board K. This fixture may be fit over an insulative housing 91 by translating the fixture upward. Also, the shell 92 may include a holding part 92a, which is formed also in a U-like cross section, and this shell 92 is fittingly placed over the insulative housing 91 and the fixture 98. In this way, the shell 92 and the fixture 98 can be retained in connection.
However, in this construction, the holding part 92a of the shell 92 needs much resiliency to hold the other parts inside. Thus, the production of the shell 92 and the assembly of the shell 92 to the fixture 98 are not simple. In addition, if a force acts to open the holding part 92a outward (shown by arrow O in the figure), there will be a problem of contact failure between the holding part 92a of the shell and the main body 98a of the fixture.